Merge branch 'x86-platform-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...

[mirror_ubuntu-artful-kernel.git] / kernel / exit.c

diff --git a/kernel/exit.c b/kernel/exit.c
index 2fb4d44c51b1f9c06346d6885d056406dc7a6079..84ae830234f8fea6328690ebf977a7063aa91097 100644 (file)
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -776,10 +776,14 @@ void do_exit(long code)
 
        exit_signals(tsk);  /* sets PF_EXITING */
        /*
-        * tsk->flags are checked in the futex code to protect against
-        * an exiting task cleaning up the robust pi futexes.
+        * Ensure that all new tsk->pi_lock acquisitions must observe
+        * PF_EXITING. Serializes against futex.c:attach_to_pi_owner().
         */
        smp_mb();
+       /*
+        * Ensure that we must observe the pi_state in exit_mm() ->
+        * mm_release() -> exit_pi_state_list().
+        */
        raw_spin_unlock_wait(&tsk->pi_lock);
 
        if (unlikely(in_atomic())) {